Audience with the Windlord

This quest has two different speeches from Thunderaan at the end depending on whether or not you've completed the original Thunderfury questline beforehand.

Original Thunderfury Questline Not Completed:

Mortal <race>. You presume much to summon me.

Ragnaros the Firelord once imprisoned me within bindings such as those you hold now.

And greedy mortals not unlike you freed me only to strike and steal my weapon, and my power.

But now that the Earthen Ring has seen to my return, I am inclined to show patience. Your errand may not be a foolish one after all.

Give me the bindings that I might turn them against the Firelord and his minions, and I will reward you in kind.

<Completion>

And so it is done, <race>. Do not call upon me again.

Original Thunderfury Questline Completed:

Mortal <race>. You presume much to summon me.

You possessed bindings such as those once before. An eternal prison from which you freed me only to jealously seek my power.

I should strike you down for what you did to me. For what you stole from me.

But now that the Earthen Ring has seen to my return, I am inclined to show patience. Your errand may not be a foolish one after all.

Give me the bindings that I might turn them against the Firelord and his minions, and I will reward you in kind.

<Completion>

And so it is done, <race>. Do not call upon me again.

There are also dialogue choices for you to make in the previous quest with the storm drake Thrymjaris in order to convince him to summon Thunderaan so that this speech can happen in the first place. They consist of either a forceful/threatening option and a soft/sweet talking option but both will have the same successful result. Either way you effectively scam Thunderaan out of some of his power because he really wants the bindings to get his revenge on the Firelord and if he simply slayed you to get them he would look evil and ungrateful to his new Earthen Ring/Shaman allies. This is ultimately why Rogues get this artifact skin instead of Warriors or Shaman. They would try to force Thunderaan to give up his power to help them and fail horribly. Instead Rogues simply make him an offer he can't refuse, as only they know how to do effectively.

"When the time comes the fire lord shall be imprisoned as I once was".

We killed Smolderon in Amirdrassil and Fyrakk basically became the new fire lord by refusing to help and absorbing him. Therefore Fyrakk is back in the elemental plane of fire after being defeated and in the future will end up imprisoned by these binding. Please Blizzard, don't forget this in Midnight or The Last Titan.